Chlorexidine and Sodium hypochlorite in root canal walls cleaning

Chlorexidine (CLX) and Sodium hypochlorite (NaOCl) are used as irrigants so that association of these solutions during root canal therapy can improve antibacterial activity. However, the inadequate use can promote a precipitate in root canal walls.Objectives: In this study was verified the root canal walls cleaning by SEM after root canal instrumentation and irrigation with 2.5% NaOCl associated 2% liquid/gelCLX. Methods: Sixty single-rooted human teeth were divided into six groups. The groups 1 to 4 were prepared by step-back technique until #35 and irrigated with 2.5% NaOCl, followed by #40 and irrigated with physiologic saline solution (PSS) and by #55 with different solutions. The group 1 - 2% CLX liquid; group 2 - 2% CLX liquid and a final flush with 17% EDTA; group 3 - 2% CLX gel inserted with PSS and group 4 - 2% CLX gel inserted with PSS and a final flush with 17% EDTA. The groups 5 and 6 was prepared by step-back technique until #55 and irrigated with PSS. In group 6 was made a final flush with 17% EDTA. SEM evaluations were made in the cervical, middle and apical thirds, with 500 and 2000X magnifications. Results: The number of open dentin tubules were evaluated, and values were statistically analyzed using ANOVA and Tukey's tests (p<0.05). There were significant statistical difference among the groups (p=0.001). It was verified that there was a high number of open dentin tubules in group irrigated with 2.5% NaOCl + 2% CLX gel + EDTA (group 4) in all root canals thirds (70% of open dentin tubules). However, the irrigation with 2% CLX (group 1) showed small amount of open dentin tubules (35%). Conclusions: The group 4 presented the most efficient technique for cleaning of root canal walls and the group 1 was less effective.